If I miss don’t claim a PS Membership download one month, will it roll over to the next month?

Yes. We allow you to accumulate a maximum of 10 credits in your account. However, If you have 10 credits on the 1st of the month (the day you receive 2 new downloads), you will lose the month's 2 new credits as we do not let you store more than 10 total credits in your account at any time.